Miter box



June 18, 1940. P NS v 2,205,019

' MITER BOX Filed May 11, 1937 4 Sheets-Sheet 1 IN V EN TOR.

' r By MN m ma June 18, 1940. v w. J. PARSONS 2,205,019 MITER BOX FiledMay 11, 1957 4 Sheets-Sheet 2 IN V EN TOR.

ATTOR June 18, 1940. w P SONS 2,205,019

MITER BOX Filed May 11, 1937 4 Sheets-Sheet 3 FRAMf 1N VEN TOR.

' A TTORNE Patented June 1 8, 1940 UNlTED STATES MITER BOX William J.Parsons, Millers Falls, Mass, assignor to Millers Falls Company,Greenfield, Mass, a corporation of Massachusetts Application May 11,1937, Serial No. 141,884

4 C lairnsf (Cl. 143-86) The present invention provides certainimprovements in the construction of miter boxes. More particularly, thepresent invention provides an improved and simplified construction ofclamping instrumentalities for stock to be sawed and means for mountingsuch instrumentalities whereby the clamping and. releasing of the stockis greatly facilitated, together with improved construction of the sawguides. 10 In accordance with the present construction,

clamping means for the stock to be sawed are provided, which clampingmeans are quickly adjustable and which are carried in novelly shaped andnovelly mounted brackets which facilitate the quick adjustment of theclamping means;

and one of the objects of the invention is to provide such bracketswhich are mounted in such a manner that they may be shifted freely andvery easily between operative and inoperative positions.

A further object of the invention is to provide locking means for thebrackets, which locking means are self-actuating responsively to thebrackets assuming operative position, so as to secure the brackets insuch position while being instantaneously releasable for enabling thebrackets to be released for adjustment or other desired purpose. I

A still further object of the invention is to provide mounting means forthe brackets for enabling adjustment of the brackets longitudinally ofthe base support for accommodating the clamping instrumentalities to anylength of stock which is to be cut. v

A still further object of the invention is to provide clampinginstrumentalities for the stock, which instrumentalities are pivotallymounted in the said brackets and which are adapted to either a quick orslow adjustment selectively relative to the stock.

A still further object of the invention is to provide mechanism formounting the said clamping instrumentalities in the brackets whilepermitting the aforesaid quick or slow adjustment of the clampinginstrumentalities responsively to the selection of the operator.

A still further object of the invention is to provide improved saw-guideconstruction which permits the ready insertion of the saw-framesupports, which also are constructed novelly for the retention of thesaw frame, the said sawguides being provided'with means for preventingaccidental displacement of the saw-frame supports therefrom.

vide improved locking instrumentalities for securing the radius bar inanydesired angular position relative to the base support.

Further objects and advantages of the present improved construction willappear hereinafter, the-novel features and combinations being set forthin the appended claims; and the invention accordingly comprises thefeatures of construction, combination of elements, and arrangement ofparts, which will be exemplified in the construction hereinafter setforth, and the scope of the application of which will be indicated inthe claims.

The invention will be understood from a consideration of the followingdetailed description, taken in conjunction with the accompanyingdrawings which show details of the improved construction in a typicalembodiment thereof, it being obvious that mechanical expedients otherthan those disclosed may be adopted, so that the drawings, therefore,are not to be taken as being restrictive in character.

In the accompanying drawings, Fig. 1 is, a front elevation of theimproved miter-box, the View including the clamping instrumentalitiesfor holding the stock in position for sawing operations, the stock beingeither metal or wood. The view indicates also certain details of themounting of the clamping instrumentalities enabling their adjustmentalong the base of the miter-box for accommodation to any length of stockbeing sawed.

Fig. 2 15a rear elevation of the miter box of Fig. 1.

Fig. 3 is a plan view of one-half of the miterbox, including theadjustable carriage for the saw and one of the quick-acting clamps forholding the stock in position.

Fig. 4 is a sectional elevation of the miterbox taken on the line 4-4 ofFigs. 1, 2 and 3 looking in the direction of the arrows and show ingcertain details of one of the quick-acting clamps and its point ofanchorage to the miterbox.

Fig. 5 is a sectional plan view through the swivel joint of one of thequick-acting clamps, the view being taken on the line 5-5 of Fig. 4,looking in the direction of the arrows, and showing details of one formof mechanism which may be employed for adapting the clamping screws foreither quick or fine adjustment relative to the stock being sawed.

Fig. 6 is a vertical section through the releasable self-actuatinglocking means for the mounting brackets for the clamping screws, theview being taken generally on either of the lines 6-5 of Figs. 1 and 2.

Fig. 7 is a detail view, partly in section, of the joint on the end ofthe clamp screw and the cup holding the clamp pad that contacts thesurface of the stock to be out.

Fig. 8 is a view partly in section and partly in elevation of certain ofthe details of construction, the view being taken on the line 8-3 ofFig. 3 and showing a side elevation of the front part of the adjustablecarriage for the saw and a vertical section through the rear part of thesaid carriage showing certain details of the locking mechanism for thesaid carriage.

Fig. 9 is a view similar to Fig. 8, but showing a side elevation of therear part of the carriage for the saw and a vertical section through thefront part of the carriage, the view being taken on the center line ofthe carriage, indicated at 99 on Fig. 3 looking in the direction of thearrows.

Fig. 10 is a front elevation of the adjustable saw carriage, the viewbeing taken on the plane of the line |5|0 of either Fig. 8 or Fig. 9,looking in the direction of the arrows.

Fig. 11 is a vertical section through the saw carriage, taken on theline of either Fig. 8 or Fig. 9, looking in the direction of the arrows.

Fig. 12 is a vertical section through the saw carriage, taken on theline |2|2 of either Fig. 8 or Fig. 9, looking in the direction of thearrows.

Fig. 13 is a vertical section through the saw carriage, taken on theline |3-i3 of either Fig. 8 or Fig. 9, looking in the direction of thearrows.

Fig. 14 is a vertical section through the saw carriage, taken on theline I i-I lof either Fig. 8 or Fig. 9, looking in the direction of thearrows.

Fig. 15 is a plan View of the locking stud lever for the radius bar ofthe saw carriage, showing the hole used to attach the lever to thelocking stud and the slot at the opposite end for the locking rod.

Fig. 16 is a view partly in section and partly in elevation of a lockingpin employed in the support for the saw frame, showing the constructionof the locking pin.

Fig. 1'7 is an end view of the locking pin of Fig. 16.

Fig. 18 is a front eelvation of one of the supports for the saw frameand a stop for the frame.

Fig. 19 is aside elevation of the parts shown in Fig. 18.

Fig. 20 is a top plan view of the parts illustrated in Figs. 18 and 19.

Before proceeding with a detailed description of the invention, it maybe mentioned that the improved miter box assembly of the presentinvention comprises, generally, a base for receiving the work or stockto be sawed, a pair of adjustably mounted brackets each carrying a quickaction clamp for engaging the said stock, and an adjustable carriage tohold, guide and control the position of the saw, the said carriageincluding improved mechanism for positively locking the carriage inadjusted position, and which prevents accidental release of the carriagefrom its adjusted position.

Referring more particularly to the drawings, it will be seen that theconstruction includes an angle box, indicated generally by A, which isused to support the work to be cut, the saw carriage assembly beingindicated generally by B, the quick action clamps for holding in theangle box B the work to be cut, being indicated generally by C, while Ddesignates generally the lock pin assemblies for the supports for thesaw frame.

The angle box assembly A comprises a frame 25, which is a substantiallyrectangular frame braced by rectangular reinforcing braces 2'! which arewelded to the frame 25, the frame being braced also by diagonal braces29 which are also welded to the frame. Secured to the frame 25 is acurved locking bar 3| which is generally semicircular in shape, andwhich is provided with attachment flanges 32 by which the locking bar isattached to the frame 25 by means of suitable bolts such as indicated at3:1.

The frame is supported by leg units 33, which are formed in any suitablemanner, conveniently from band stock which is bent to product the frontand rear legs, each of the leg units extending transversely across theframe 25 on the underside thereof and which are welded to the frame.

The frame 25 carries a pair of table plates 35. 35, these plates havingtheir adjacent edges at a sufiicient angle to each other so as to enablethe saw carriage to operate between the plates and be adjusted to anangular position of at least 45 on each side of the center line. Thetable plates 35, 35 rest upon spacers 37, each of which spacers extendscontinuously around and beneath the respective plates 35, the latterbeing held in place on the spacers 37 and frame 25 by means of clampinghooks 39 which are anchored in the plate 35 and extend around the framemembers 27, 29 and 3|.

An upstanding corrugated back plate 4| is bolted to the frame 25 bymeans of the bolts 34 previously described, and additional bolts 36which pass through the corrugated plate and into the frame 25, which isprovided with tapped holes for this purpose.

Adjacent to each end of the miter box assembly is a clamping assembly,designated generally by C, each of which is of identical construction,so that only one of these assemblies needs to be described in detail.Each clamping assembly C comprises an arm 43, which may be a dropforging, which is bent to form a pivot section 38 which is hinged on apivot pin extending longitudinally of the miter box behind thecorrugated plate 4|, the pin 55 being mounted in supports 4! which aresecured to the corrugated plate A! by means of screws 49. The arm 33 isturnable free- 1y about the pin 45 and is slidable along the pin so asto be adjustable for any length of stock to be cut.

The arm 43 includes also a bend All at which is mounted a clamping screw6|, which will be described in detail hereinafter. The bend in the arm33 produces a bow in the arm which provides effective resistance toclamping stresses communicated to the arm 43 through the screw 6|, aswell as providing a proper shape to the arm 43 for enabling the arm toengage the plate 35 when the arm is in secured position. This engagementis effected in the region of the free end 32 of the arm 63, which end isshaped and recessed to form a housing 48 (Fig. 6) in which is inserted alock pin 5| which is retractably mounted in the housing 48 and which isheld normally in expanded or locking position by means of a spring 53,which encloses a shank 42 of the pin 5| and which is compressed betweenthe shoulder of the pin and the internal shoulder 46 of the housing 48.A handle or knob is threaded on the end of the shank 42' of the pin 5|,this handle knob retaining the pn 5| in its housing and also providingmeans whereby the pin may be retracted against the pressure of thecompressed spring 53 so as to withdraw the pin 5| from its engagementwith the frame 25, thus releasing the arm 43 for enabling the latter tobe swung about the pivot pin 45, or moved along the pin for adjustmentof the position of the arm 43.

The work to be cut is inserted in the miter box on the base plates 35,35 by releasing and raising the arms 49 in the manner described above,and when the work is in proper position for cutting operation, the armis dropped back into position, whereupon the lock pin 5| first strikesagainst the frame 25 so as to compress the spring 53 until the pin 5| isenabled to clear the frame 25. When this occurs, the spring 53 expandsthe lock pin 5| back into locking position, whereby the arms 43 becomeagain rigidly secured in locking position It has been said that a clampscrew 6| is mounted at the bend 40 of each of the arms 43. For thispurpose, a holder II, which will be described in detail hereinafter, ismounted in the arm 43, the screw 6| passing through this holder. Theclamp screw BI is operated by turning its handle knob 59, which forces aworkcontact pad 63, mounted on the lower end of the screw 6|, againstthe work to be cut, by transferring pressure exerted on the screwthrough a ball connector 65 (Fig. 7) on the end of a cup 61 and a socket69 in the lower end of the clamp screw 6|. This ball joint connectionfor the pad 63 enables a firm clamping action to be had on any piece ofwork regardless of the shape thereof, since the engagement of the padwith the work is conformable freely to the shape thereof responsively topressure exerted by the screw 5|.

The screw 6| is adapted to be quickly adjusted relative to the work, byin and out movement as designated by the arrow 62 in Fig. 4. In order toobtain this quick motion, a special mounting mechanism is provided whichincludes the holder H, which has been mentioned previously above.

In order to accommodate this holder, the bend 49 of the arm 43 isprovided with a bifurcated enlargement 12 (Fig. 5) which is apertured toreceive a sleeve H which is inserted in openings 95 provided in lugs 14formed one on each section of the enlarged portion 12 of the arm 43.This sleeve H is apertured to permit the clamping screw 6| to passfreely crosswise through it and is closed at one end and forms a housingfor receiving a spring 19 which is compressed between the end of thesleeve 11 and the holder "H, as will be apparent from Fig. 5. The holderl I therefore constitutes a spring pressed plunger or piston which has ahole 15 therethrough for receiving the clamping screw 6|.

This hole 15 is of a generally elliptical shape, as will be seen fromFig. 5, and it is provided with internal threads '13 which engage theclamping screw GI, the threads 13 being a half section of a full thread,the other half of the hole 75 being unthreaded, the configuration of thehole providing a clearance between the smooth or unthreaded portion ofthe hole and the clamping screw 5|, so that when pressure is applied tothe end of the plunger H of sufficient magnitude to overcome thepressure of the spring 19, the plunger H is moved inwardly so as toclear the engagement between the threads 13 of the hole 15 and theclamping screw 6|, thus releasing the latter for free sliding movementthrough the hole to give a quick adjustment of the clamping screwrelative to a piece of work to be cut. The movement of the plunger H isindicated clearly by the arrow 89 in Fig. 5.

When the parts are in the position indicated in Fig. 5, the clamp screw6| is not free for a quick adjustment thereof relative to the work, butit is held by the thread 13 and can be advanced or retracted relativelyto the work only I by a turning movement of the screw, which providesfor a fine adjustment of the clamping screw; while, when the screw 6| isreleased by pressure applied to the plunger 1| so as to overcome theforce of the spring 19, the threads 13 are moved out of engagement withthe threads on the clamping screw, so that the latter is released forquick movement incident to the disengagement of the threads asaforesaid.

A safety catch for plunger may be provided, such as pin 8| set inplunger II and slidable therewith in slot 83 which is sufficiently longto allow sufiicient movement to the plunger to engage and release pin6|. An opening 81 is provided in the arm 43 for enablingangularadjustment of the clamp screw 6| about the center of the sleeve11.

With this arrangement of the quick acting clamp, work parts in the formof irregular cross sections, such as, for instance, metal or woodmolding, may be quickly clamped in position in the miter box.

Reference may now be made to the supporting assembly for the saw.

This assembly is indicated generally by the character B, and inc-ludes'afront support 89 and a rear support 9| which are adapted to receive thesaw frame, indicated generally at 92. These supports 89 and 9| arecarried by the saw frame which passes through slots 93 and 95 providedfor this purpose in the supports 89 and 9|, the saw frame 92 slidingback and forth in these slots.

The slots 93 and 95 are provided in an enlarged head portion 96 of thesupports 89, 9|, the remainder of these supports being of a morerestricted diameter and being in the form of an elongated rod adapted tobe inserted in the tubular holders 3, H5, which will be mentioned ingreater detail hereinafter.

The saw frame 92 is held in the slots 93 and 95 by spacers 91 and 99which are inserted in the upper part of the slots, and which becomeflush with the periphery of the supports 89, 9|, when properly inserted.These spacers 91 and 99 are held in the supports 89 and 9| by means of ascrew I91, which secures the spacers in position and positively retainsthe saw frame in the slots 93 and 95 so that there is no possibility ofaccidental displacement of the saw frame from these slots.

The front and rear supports 89 and 9| are each provided with a stop |9|for controlling the low position of the saw blade, the stop |9| engagingthe upper end of the tubular holders H3 and H5, respectively, when thesaw frame and supports are mounted in operative position. The stops |9|are secured in their position of desired adjustment by means of a screw95.

The sides of the slotted ends of the front and rear supports 89 and 9|are toothed at I93, shown in Figs. 18, 19 and 20, these teeth |93matching the corresponding teeth formed on the end of the stop ml. Thisarrangement prevents the slipping of stop l9! when the screw I95 istightened. It will be seen clearly from Fig. 19 that the stop |9| isprovided with a longitudinal slot ing.

I92 which receives the screw I95, whereby when the screw I95 isreleased, the stop I9! is released so that it may be adjusted as desiredrelatively to the support.

A vertical slot I99 (see, for example, Figs. 10 and 11) is provided nearthe lower end of the front and rear supports 99 and 9I for the insertionof a saw blade I I9, when the blade is clamped into the saw frame. Theupper end of the slot I09 is made narrow, as indicated at III (see Figs.8, 9 and 10, for example) to form a guide for the saw blade I ID, theback of the saw blade being received in the restricted portion III ofthe slot, and is prevented thereby from buckling during operation.

The front support 39 is held in position by a holder H3, and the rearsupport 9! is received in holder II5, these holders being tubular forthe reception of the supports. The holder H3 is supported on a bar I llwhich forms a. part of the saw carriage assembly,-and holder H5 issupported by a bar H9 which also forms a portion of the saw carriageassembly. The bar II! is provided with a groove I2I on the under sidethereof, (see Figs. 11 and 13) and bar II9 is provided with a shoulderI23 which is adapted to fit into the groove I2I, the bars H7 and H9being held together in assembled relation by means of a screw I25 whichpasses through these bars. This construction may be seen in Fig. 11, forexample. The holders II3 and H5 are provided with a clearance slot I2!for allowing the saw to be dropped to its low position.

For facilitating the handling of the saw when placing work in the miterbox, or when changing saw blades, locking pins D are provided near thetop of the holders H3 and i i5, so that when the saw frame is lifted,the supports 89, 9I lock with the pins to hold the saw in raisedposition.

The details of the construction of these looking pins are shown in Figs.16 and 17. The pin proper, indicated at I29, is received in a housingI3I, the pin I29 having a shank portion I39 which extends through anopening provided therefor in the end of the housing, and which isthreaded, as indicated at I32, for receiving a handle member I35, whichis shown as being a knob threadedly attached to the pin shank I39.

The shank I39 defines an annular shoulder I34 with the pin I29, and thehousing I3I is provided with an internal annular shoulder I35, therebeing a coil spring I33 compressed between the shoulders I34 and I36,thereby urging the pin I 29 in extended position, retraction of the pinfor insertion of the saw frame supports in the tubular holders beingeffected by a pull on the handle I35 sufiicient to overcome the pressureof the spring. The handle I35 also holds the pin in the housing I3I.

The locking pin I29 is provided with a fiat surface I37 which fits in acorresponding hole I38 formed in the end of the housing I3I, therebypreventing turning of the locking pin in the hous- Additionally, the endof the locking pin I29 is provided with a bevelled shoulder I49, and aflat shoulder I40, which shoulders enable the locking pin to fit in anannular groove I42 (see Fig. 9) on the lower end of the frame supports89, 9|. Threads I39 are provided on the end of the locking pin housingI3I, as is shown clearly in Fig. 16, for securing the pins in thetubular holders II3, II5.

When the saw is operating on the work, or is resting in its lowposition, the locking pins I29 ride against the surface of therespective supports 89, 9I, because of the pressure of the spring I 33against the pin I29. It is obvious, therefore, that when the saw israised to its high position the locking pins I29 will be forcedautomatically into the grooves I42 of the supports, thus causing the sawto be held in its high position while at the same time looking the sawagainst accidental removal from the holders H3, H5. When the saw is tobe lowered or removed from the tubular holders, the handle knobs I35 arepulled outwardly until disengagement is effected between the lockingpins I29 and the grooves I42, thereby releasing the supports 89, 9I.

Considering now the assembly making up the adjustable saw carriage, itwill be seen that this assembly includes the tubular holders H3, H5, andthe bars II? and H9 which have been referred to previously, thisassembly being swivelly anchored to the frame 25 by means of a swivelstud I44, (see Figs. 3, 8 and 9) which stud is received in a suitablehole extending through reinforcing bars I4I and I43 (see especially Fig.3) which bars are welded to the frame 25. The stud I44 is fastened inthe bar II9 by means of threads I46 (Fig. 8) on the end of the stud I44,which threads engage with threads in a tapped hole- I48, a set screw I(Fig. 9) being provided for locking the stud I44 in the bar II9.

Additional support for the saw carriage assembly is afforded by theprovision of a clamp bar I49 which rests on the reinforcing bar I43 ofthe frame 25, and the arcuate locking bar 3|. This clamp bar I49 isfastened to the bar II9 by means of a stud I5I which passes through aslot I52 in the bar IIl (see Figs. 8 and 9), the stud I5I being securedin place by a screw I53 which enters the stud through the lower endthereof. Additional connection between the clamp bar I49 and the bar H9is made by means of a stud I55 which is held by means of a screw passingthrough the bar H9 and into the stud as will be apparent from Figs. 8and 9. A clearance groove I59 is provided in the clamp bar I49 for theteeth on the saw blade III).

In addition to its supporting function, the clamp bar I49 also functionsas a support for the parts of the work being cut, on either side of thesaw blade, preventing the said parts from binding the blade duringsawing.

The mechanism for locking the saw carriage assembly is shown especiallyin Figs. 3, 8 and 9, this mechanism enabling the said assembly to belocked in any radial position within a 45 angle on either side of thecenter line of the miter box.

This locking mechanism for the saw carriage assembly includes a lockingstud I6! which has a threaded end I62 entering the clamp bar I 49, thestud I6I being swivelled in the bar II9 as will be seen clearly in Figs.8, 9 and 14. Turning movement of the stud I6I is effected by means of alever I63 which is secured to the stud I6I by means of a flat sideshoulder I65 (see Fig. 14) on the stud I6I, corresponding to a suitablehole I67 in one end of the lever I63 (see Fig. 15). A look nut I69 holdsthe lever I63 against shoulder I64 of the stud I6I. A washer I'II isprovided on the stud I6I between the bar H9 and the lever I63 foravoiding frictional wear between these parts.

The lever I63 is operated by actuation of a rod I'I3 (Figs. 3, 8 and14), which has one end, I14, formed so that it enters slot I15 in thelever I63. Washers I'I'I are provided on rod I 13 on either side of thelever I63, the end, I'I4, of the rod being headed over at I19 to holdthe washers in place and to prevent disengagement of the rod from thelever. The rod I13 is supported in position by supports I8I, I83, whichare, conveniently, screw-eyes positioned in tapped holes in bar H9. Theoperation of this locking mechanis will be referred to hereinafter.

The carriage assembly B for the saw is adjustable to enable the saw tocut at angles up to 45 on either side of the center line, as has beenindicated above. For this purpose,'the arcuate locking bar 3| isprovided with slots or notches I (Figs. 8, 9 and 12), which slots areengaged by a locking pin I81 which slides through a hole I88 in the barH9. The pin I81 is held in the locked position by the pressure of aspring I99 against a lever I9I (see Fig. 11). This lever I9I has its endslotted so that it straddles the pin I81 (Figs. 11 and 12), and rests ina groove I93 in the pin I81. The pin I81 is withdrawn from slot I85 byupward pressure exerted on the front end of a second lever I whichengages. the lever I9I on the under side of the latter, and which isprovided with a slot 209. A stud 295 is riveted in the lever I9I andpasses into the slot 209 to form a sliding support for the lever I95.

The bar II9 also holds a stud I91, which stud passes through a hole I99in the lever I9I and through the slot 299 in the lever I95, this studI91 carrying fulcrum pins 293, 294 for levers I9I and I95. The mountingof the levers I9I and I95 is such that a slight relative longitudinalmovement therebetween is produced upon an exertion of sufiicientpressure on the end of lever I95 to move this lever against the pressureof spring I89 so as to compress this spring and at the same time causinglever III! to pull downwardly on the pin I81 because of the engagementof the lever I 9| in the groove I93 of the pin I81, thereby disengagingthe latter from its locking position in slot I85, so that the sawcarriage mechanism may be adjusted to the desired angular position.

The design of the lever mechanism for actuating the locking pin I81'issuch that there is no tendency of the locking pin I81 to bind in thehole I88, but the movement is always smooth and positive. This is due tothe mounting of the levers I9I and I95 to permit the relatively slightmovement therebetween, and also because of the elimination of fixedpivot points which would cause the locking pin I81 to travel in anarcuate course during its movement.

Such fixed pivot points are replaced by the fulcrum pins 203, 294 overwhich slide the levers I9I, I95. The longitudinal sliding action betweenthe levers I9I, I95 is only slight, but because of the clearance in thehole I99 around the stud I91, and the clearance of hole 2II around pin291, to be described hereinafter, together also with the fact that theslot 299 in the lever I95 clears the shoulder ZI9 on the stud 205, andalso because of the fact that the end of the lever I9I slides in theslot I93 in the pin I81, the movement of the pin I81 becomes a straightline movement instead of following an arcuate path.

Any binding from a side action that might be caused by pin I81 in thehole I88 in the bar H9 is eliminated by the side support provided bylever I95, and lever I9I, and the clearance of hole I99 around the pinI91, together with the.

fact that levers I91 and I95 are free to slide sideways on fulcrum pins293, 294. It will be seen, accordingly, that levers I9I and I95 have afloating motion between them inv both longitudinal'and lateraldirections so as to maintain the pin I81 free from any binding action inits movement.

In order to guide the vertical movement of the lever I95,a pin 291 isheld in the bar In and '5" serves as a .guide for the lever I95, as wellas limiting the longitudinal movement thereof, the lever I95 beingprovided with a hole ZII for receiving the pin 201. The slot 299 in thelever I95 clears the pin I81, stud I91, and stud 295, and 1'0 terminatesrearwardly of the clearance hole ill I.

From the above, it will be seen that when the lever I95 is pressed up torelease the pin I81 for freeing the saw carriage assembly, the latter 7swivels around the stud I44 into the desired 1",, angular adjustment.When it is properly adjusted, the saw carriage assembly may be lockedagainst accidental displacement by actuating the rod I13, by means ofits handle end I19, this actuating the lever I63 to turn the stud IN, 20which draws the clamp bar M9 and the bar H9 towards each other by actionof the thread I92 on the end of the stud I6! sufficiently to clamp thebars together against the top and bottom surfaces of the locking bar 3|.Release thereof is effected by opposite actuation of the rod I13 andlever I99.

Notches I85 may be positioned at angles which are frequently used, sothat the saw assembly may be quickly adjusted to such angles with thehelp of the locking pin I81. Of course, the saw assembly may be lockedat any other angle where his; pin I81 does not engage one of the notchesThe distance between the saw supports 89 and 9| may be adjusted tochange the length of move-' ment of the saw or to provide for blades ofdifferent lengths. From an inspection of Fig. 9 it will be seen that byloosening the screw I25, the bar H1 carrying the holder H3 may be drawnoutwardly until the rear end of the slot I52 strikes the screw I25.During this movement the pin 291 will carry the lever I95 outwardly, asthe slot 209 slides over the shoulder ZIIl of the stud 295, and thelever I95 slides over the pivot I299. When the desired position for theholder H9 is reached the screw I25 is tightened, whereupon the lockingmechanism will function as before.

It is believed that the operation of the various parts of the presentimproved construction will be apparent from the foregoing description,and that no further reference to the operation of the parts needs to begiven.

From the foregoing detailed description, it will be understood that theinvention is not limited, necessarily, to the specific details of theconstruc- 55 tion as are herein specifically illustrated and described,as it will be apparent that such details are subject to variousmodifications which will become apparent readily to one skilled in theart, without departing from the spirit of the inven- 60 tion; and itwill be understood, therefore, that it is intended and desired toinclude within the scope of the invention such modification and changesas may be necessary to adapt it to varying conditions and uses. It isalso to be under-- 65 stood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall there- 70 between.

What is claimed is: I

1. In a miter box, means for clamping material to be sawed comprising incombination, a curved arm; means for securing each end of said arm to 76said miter box; a sleeve journaled in said am and provided with a pairof opposite apertures; a clamp screw slidably mounted in said apertures;a piston reciprocable in said sleeve, said piston being provided with anelliptical aperture adapted to coincide with the apertures in saidsleeve, said aperture being provided at its narrow end with half threadsadapted to fit the threads on said clamp screw, said clamp screw beingslidable axially through the wide end of said aperture; and means forreciprocating said piston to change the position of said clamp screw insaid aperture and so to permit slow or fast adjustment thereof.

2, In a miter box, means for clamping material to be sawed comprising incombination, a curved arm; means for securing each end of said arm tosaid miter box; a sleeve journaled in said arm and provided with a pairof opposite apertures; a clamp screw slidably mounted in said apertures;a piston reciprooable in said sleeve, said piston being provided with anelliptical aperture adapted to coincide with the apertures in saidsleeve, said aperture being provided at its narrow end with half threadsadapted to fit the threads on said clamp screw, said clam screw beingslidable axially through the wide end of said aperture; and spring andstop means for controlling reciprocation of said piston to change theposition of said clamp screw in said aperture and so to permit slow orfast adjustment thereof.

3. In a miter box, means for clamping material to be sawed comprising incombination, a curved arm; means mounted on said miter box providing apivot for one end of said arm, said arm being slidable along said pivotmeans; substantially instantaneously releasable means for securing theother end of said arm to said miter box; a sleeve journaled in said armand provided with a pair of opposite apertures; a clamp screw slidablymounted in said apertures; a piston reciprocable in said sleeve, saidpiston being provided with an elliptical aperture adapted to coincidewith the apertures in said sleeve, said aperture being provided at itsnarrow end with half threads adapted to fit the threads on said clampscrew, said clamp screw being slidable axially through the wide end ofsaid aperture; and means for reciprocating said piston to change theposition of said clamp screw in said aperture and so to permit slow orfast adjustment thereof.

4. In a miter box, means for clamping material to be sawed comprising incombination, a curved arm; a pin mounted on said miter box providing apivot for one end of said arm, said arm being slidable along said pin;spring controlled releasable means for locking the other end of said armto said miter box; a sleeve journaled in said arm and provided with apair of opposite apertures; a clamp screw slidably mounted in saidapertures; a piston reciprocable in said sleeve, said piston beingprovided with an elliptical aperture adapt- WILLIAIW J. PARSONS.

